Safer oil and gas development in ultra-deep waters

Developing safety engineering for floating offshore platforms.

Oil and gas development under the sea has traditionally been made possible via offshore platforms, which are fixed to the seabed. However, these types of platform are only useful in shallow waters. When developing oil and gas fields in deep and ultra-deep waters (more than 1,000 metre water depth), developing a footing for platforms onto the seabed is difficult and lacks stability.

As a result, ship-shaped floating offshore platforms work better for deep and ultra-deep water environments. These floating platforms also have storage tanks, meaning pipeline infrastructure to transport energy resources to shore is unnecessary. These ship-shaped floating platforms are multi-functional, with the ability to produce, store and offload oil and gas. Yet floating offshore platforms are also subject to risks from extreme conditions, and the possibility of fires and explosions.

In response to this, Professor Jeom-Kee Paik from UCL Mechanical Engineering developed a research project to advance safety design and engineering procedures for ship-shaped offshore installations. This research was funded by the Lloyd’s Register Foundation, in association with the research programme for ‘Engineering a safer world’.

Extreme conditions and accidents

“Accidents are the result of volatile, uncertain, complex and ambiguous (VUCA) environmental and operational conditions,” Professor Paik explains. “The utilization of risk-based methods along with the probabilistic characterization of all aspects is recognized as the best way to resolve such challenges.”

This is where Professor Paik’s team started their work. They developed procedures for the quantitative risk assessment and management of accidents. Once they were happy with the procedures, they applied them to large scale physical testing to actual engineering structures in accidents.

Importantly, the team designed different procedures for different types of risks and accidents, such as fires, explosion, collisions, grounding and sinking. For example, the procedure for quantitative explosion risk assessment and management accounts for factors including weather conditions, realistic explosion scenarios and blast loads, as well as aspects such as pressure, drag force and impulse. The procedure also calculates things like the risk of structural collapse and the impact of decision making in the scenario.

The factors feeding into other types of risks and accidents would be different from different types of accidents, yet a set of procedures can still be put in place to calculate risk through Professor Paik’s method. “Such procedures are a kind of recipe, like for cooking food.”

Making floating offshore platforms safer

The technologies that Professor Paik and his team developed are useful for safety engineering at every stage of the lifecycle of floating offshore platforms. The methods can be used in the design, construction, operation, lifetime healthcare and decommissioning of these platforms. Not only were the team able to create advanced safety methods for ‘traditional’ types of accidents, including hull girder collapse, collisions, fires and explosions, but also for events such as earthquakes, hurricanes and terrorist attacks.

These technologies are now becoming industry practices embedded into advanced safety design and engineering procedures. The ALPS software is being used by 90 organisations in 23 countries for ultimate limit states-based safety design and engineering. Essentially, the methods developed by the team have made it possible to effectively manage VUCA environments, and resolve the challenges associated with ship-shaped offshore installations in relation to extreme conditions and accidents. They will help to decrease the number of maritime casualties that occur.